scsi: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare variable-length
types such as these ones is a flexible array member[1][2], introduced in
C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200224161406.GA21454@embeddedor
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Gustavo A. R. Silva 2020-02-24 10:14:06 -06:00 committed by Martin K. Petersen
parent 5905d4648e
commit 5febf6d6ae
16 changed files with 27 additions and 27 deletions

View file

@ -442,7 +442,7 @@ struct vnic_devcmd_notify {
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
u8 data[0];
u8 data[];
};
/*

View file

@ -451,12 +451,12 @@ struct ipr_config_table_hdr64 {
struct ipr_config_table {
struct ipr_config_table_hdr hdr;
struct ipr_config_table_entry dev[0];
struct ipr_config_table_entry dev[];
}__attribute__((packed, aligned (4)));
struct ipr_config_table64 {
struct ipr_config_table_hdr64 hdr64;
struct ipr_config_table_entry64 dev[0];
struct ipr_config_table_entry64 dev[];
}__attribute__((packed, aligned (8)));
struct ipr_config_table_entry_wrapper {
@ -792,7 +792,7 @@ struct ipr_mode_page28 {
struct ipr_mode_page_hdr hdr;
u8 num_entries;
u8 entry_length;
struct ipr_dev_bus_entry bus[0];
struct ipr_dev_bus_entry bus[];
}__attribute__((packed));
struct ipr_mode_page24 {

View file

@ -201,7 +201,7 @@ struct smp_req {
u8 func; /* byte 1 */
u8 alloc_resp_len; /* byte 2 */
u8 req_len; /* byte 3 */
u8 req_data[0];
u8 req_data[];
} __packed;
/*

View file

@ -207,7 +207,7 @@ struct fw_event_work {
u8 ignore;
u16 event;
struct kref refcount;
char event_data[0] __aligned(4);
char event_data[] __aligned(4);
};
static void fw_event_work_free(struct kref *r)

View file

@ -394,7 +394,7 @@ struct mvs_info {
dma_addr_t bulk_buffer_dma1;
#define TRASH_BUCKET_SIZE 0x20000
void *dma_pool;
struct mvs_slot_info slot_info[0];
struct mvs_slot_info slot_info[];
};
struct mvs_prv_info{

View file

@ -130,7 +130,7 @@ enum {
struct mvumi_hotplug_event {
u16 size;
u8 dummy[2];
u8 bitmap[0];
u8 bitmap[];
};
struct mvumi_driver_event {
@ -290,7 +290,7 @@ struct mvumi_rsp_frame {
struct mvumi_ob_data {
struct list_head list;
unsigned char data[0];
unsigned char data[];
};
struct version_info {

View file

@ -623,7 +623,7 @@ struct pmcraid_aen_msg {
u32 hostno;
u32 length;
u8 reserved[8];
u8 data[0];
u8 data[];
};
/* Controller state event message type */

View file

@ -208,7 +208,7 @@ struct vnic_devcmd_notify {
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
u8 data[0];
u8 data[];
};
/*

View file

@ -236,7 +236,7 @@ struct req_msg {
u8 data_dir;
u8 payload_sz; /* payload size in 4-byte, not used */
u8 cdb[STEX_CDB_LENGTH];
u32 variable[0];
u32 variable[];
};
struct status_msg {

View file

@ -311,7 +311,7 @@ enum iscsi_param_type {
struct iscsi_param_info {
uint32_t len; /* Actual length of the param value */
uint16_t param; /* iscsi param */
uint8_t value[0]; /* length sized value follows */
uint8_t value[]; /* length sized value follows */
} __packed;
struct iscsi_iface_param_info {
@ -320,7 +320,7 @@ struct iscsi_iface_param_info {
uint16_t param; /* iscsi param value */
uint8_t iface_type; /* IPv4 or IPv6 */
uint8_t param_type; /* iscsi_param_type */
uint8_t value[0]; /* length sized value follows */
uint8_t value[]; /* length sized value follows */
} __packed;
/*
@ -697,7 +697,7 @@ enum iscsi_flashnode_param {
struct iscsi_flashnode_param_info {
uint32_t len; /* Actual length of the param */
uint16_t param; /* iscsi param value */
uint8_t value[0]; /* length sized value follows */
uint8_t value[]; /* length sized value follows */
} __packed;
enum iscsi_discovery_parent_type {
@ -815,7 +815,7 @@ struct iscsi_stats {
* up to ISCSI_STATS_CUSTOM_MAX
*/
uint32_t custom_length;
struct iscsi_stats_custom custom[0]
struct iscsi_stats_custom custom[]
__attribute__ ((aligned (sizeof(uint64_t))));
};
@ -946,7 +946,7 @@ struct iscsi_offload_host_stats {
* up to ISCSI_HOST_STATS_CUSTOM_MAX
*/
uint32_t custom_length;
struct iscsi_host_stats_custom custom[0]
struct iscsi_host_stats_custom custom[]
__aligned(sizeof(uint64_t));
};

View file

@ -52,7 +52,7 @@ struct iscsi_bsg_host_vendor {
uint64_t vendor_id;
/* start of vendor command area */
uint32_t vendor_cmd[0];
uint32_t vendor_cmd[];
};
/* Response:

View file

@ -230,7 +230,7 @@ struct scsi_device {
struct mutex state_mutex;
enum scsi_device_state sdev_state;
struct task_struct *quiesced_by;
unsigned long sdev_data[0];
unsigned long sdev_data[];
} __attribute__((aligned(sizeof(unsigned long))));
#define to_scsi_device(d) \
@ -314,7 +314,7 @@ struct scsi_target {
char scsi_level;
enum scsi_target_state state;
void *hostdata; /* available to low-level driver */
unsigned long starget_data[0]; /* for the transport */
unsigned long starget_data[]; /* for the transport */
/* starget_data must be the last element!!!! */
} __attribute__((aligned(sizeof(unsigned long))));

View file

@ -683,7 +683,7 @@ struct Scsi_Host {
* and also because some compilers (m68k) don't automatically force
* alignment to a long boundary.
*/
unsigned long hostdata[0] /* Used for storage of host specific stuff */
unsigned long hostdata[] /* Used for storage of host specific stuff */
__attribute__ ((aligned (sizeof(unsigned long))));
};

View file

@ -27,7 +27,7 @@ struct scsi_device;
typedef struct scsi_ioctl_command {
unsigned int inlen;
unsigned int outlen;
unsigned char data[0];
unsigned char data[];
} Scsi_Ioctl_Command;
typedef struct scsi_idlun {

View file

@ -109,7 +109,7 @@ struct srp_direct_buf {
struct srp_indirect_buf {
struct srp_direct_buf table_desc;
__be32 len;
struct srp_direct_buf desc_list[0];
struct srp_direct_buf desc_list[];
} __attribute__((packed));
/* Immediate data buffer descriptor as defined in SRP2. */
@ -244,7 +244,7 @@ struct srp_cmd {
u8 reserved4;
u8 add_cdb_len;
u8 cdb[16];
u8 add_data[0];
u8 add_data[];
};
enum {
@ -274,7 +274,7 @@ struct srp_rsp {
__be32 data_in_res_cnt;
__be32 sense_data_len;
__be32 resp_data_len;
u8 data[0];
u8 data[];
} __attribute__((packed));
struct srp_cred_req {
@ -306,7 +306,7 @@ struct srp_aer_req {
struct scsi_lun lun;
__be32 sense_data_len;
u32 reserved3;
u8 sense_data[0];
u8 sense_data[];
} __attribute__((packed));
struct srp_aer_rsp {

View file

@ -209,7 +209,7 @@ struct fc_bsg_host_vendor {
__u64 vendor_id;
/* start of vendor command area */
__u32 vendor_cmd[0];
__u32 vendor_cmd[];
};
/* Response: